41. Xylem moves water and inorganic molecules within the plant and phloem accounts for organic molecule transportation. 42. The fibres of the xylem are always lignified, while those of the phloem are cellulosic. 43. The phloem limited positive sense RNA virus infects potatoes and other members of the family Solanaceae. 44. The data showed that beet leafhoppers primarily ingested phloem sap along with xylem and mesophyll sap. 45. The trunk is composed of sleeves of conductive tissue, most notably the phloem and xylem. 46. The larvae initially excavate cavities in the phloem and cambium and later galleries into the wood. 47. They bore into the bark and feed on the phloem at base of their host plant. 48. The vascular bundles of the stem are arranged such that the xylem and phloem form concentric rings. 49. The causative agents are fastidious phloem -restricted, Gram-negative bacteria in the gracilicutes clade. 50. Inside the phloem is a layer of undifferentiated cells one cell thick called the vascular cambium layer.
